Providing a user interface for a particular device can present a number of challenges. Conceptually, a user interface needs a control device or devices that can be manipulated by the human user to provide input to control a particular device. Some user interfaces also incorporate a display device or other indicators for presenting information about the device or for showing a response to user input entered with the control device.
A common type of user interface is a graphical user interface (“GUI”). A GUI is typically used with a computer or similar device that incorporates a display device. The GUI includes icons and windows that are displayed by the device and can be selected and manipulated using appropriate control devices, for example, a mouse and keyboard. A GUI provides great flexibility in that it can be adapted to receive a wide variety of user input to control a wide variety of diverse applications. However, to implement a GUI, the device generally has to have an existing display device and the processing power to support the programming for the GUI. Additionally, the device must usually support such peripherals as a mouse and keyboard for receiving the user input to the GUI. This entails both space and cost requirements. Finally, a GUI is not well adapted to the rapid adjustment of operational parameters on a very fine level or in a continuous manner, such as is available with a dedicated dial or knob.
In some examples, a GUI is implemented with a touch sensitive screen. The touch sensitive screen displays the GUI elements, but does not have to receive input using a mouse or keyboard. Rather, user input is received by sensing a physical touch against the screen to select a displayed element, such as an icon or button. Such interfaces are good for operating menus and turning options on and off. However, like other GUIs, touch sensitive screens are not well adapted for the rapid fine tuning of operational parameters.
Other types of user interfaces may not include any display device, but simply include various control devices for receiving user input. Examples of devices that include such interfaces include audio equipment such as mixer boards. Such interfaces can include knobs or dials for rapidly entering fine adjustments to operational parameters in a continuous manner. However, if there are a large number of operational parameters to control, the number of control devices needed may be large and difficult to accommodate in a reasonably compact interface.